QtOpenGL GL_BGR not defined

[^NyAw^]

Hi,

Following the instructions on GameDev it seems to work.
Searching into my computer I have found that there is a "gl.h" in this folder "C:\Documents and Settings\All Users\Datos de programa\NVIDIA Corporation\NVIDIA GPU Computing SDK 4.0\shared\inc\GL" that contains the "GL_BGR" definition. This folder was created when I installed Nvidia CUDA SDK as I want to use OpenGL on OpenCV to improve performance.
Maybe changing the libs it will work but I'm a little confused:
- I can make my application to use this header lib
- In the folder "C:\Documents and Settings\All Users\Datos de programa\NVIDIA Corporation\NVIDIA GPU Computing SDK 4.0\shared\lib\Win32" there are 3 libs "freeglut.lib" "glew32.lib" and "shrUtils32.lib"
- Qt is already linked to OpenGL libs
So, changing the header in my application will work? Or maybe have to recompile Qt pointing to this new OpenGL libs?

Thanks all,

[high_flyer]

So, changing the header in my application will work?

It will work, if its only a matter of a missing define in a header, but implemented in the lib.
Otherwise it wont.
If your Qt is compiled with its own OGL, don't mix.
What you can do, is rebuilt Qt to use an OGL that you specify, then you can specify what ever other OGL lib you have, which Qt then will use.

[^NyAw^]

Hi,

What you can do, is rebuilt Qt to use an OGL that you specify, then you can specify what ever other OGL lib you have, which Qt then will use.

In this moment the above solution does what I need but I don't discard try this solution in future.

Thanks,

[wysota]

It's just a define, a number. It doesn't matter what it is called, you can even define it in your own sourcecode.

#ifndef GL_BGR
#define GL_BGR 0x80E0
#endif

#ifndef GL_BGR
#define GL_BGR 0x80E0
#endif

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[high_flyer]

Yes, the compile error is not the problem.
The question is, if this define is really used in the implemented lib, or more importantly used with the same meaning.

[wysota]

One can check the version of OpenGL supported by the available GL library. I don't know if it's enough to be sure BGR is available (but I think it should pretty much always be available, BGR is a standard format).

[high_flyer]

Yes, I think so too, but better safe than sorry
I mean, I was really surprised that this define was not defined in windows... so who knows...

[wysota]

I think it depends on the OpenGL vendor. I don't know who is the GL vendor on Windows, Microsoft? GFX card producer? Anyway, it's not suprising some defines have the _EXT suffix, it's quite natural, so I'd always check for both GL_SOMETHING and GL_SOMETHING_EXT. It should be safe.